50 BULLETIN 618, U. S. DEPARTMENT OF AGRICULTURE. 
Cascade Ranges, excluding the humid portions of northern Idaho 
and northern Washington. The semiarid coastal area comprises 
only the two great interior valleys of California. The Willamette 
Valley of Oregon and the Puget Sound section of Washington are 
humid. 
The chief agricultural lands of the basin area mostly lie at alti- 
tudes of 4,000 to 6,000 feet. This includes most of the dry-farmed 
districts in Utah, Idaho, Nevada, and Oregon, often called the 
Great Basin. It comprises the Salt Lake Basin of Utah, the Snake 
River Basin of Idaho, the Humboldt Basin of northern Nevada, 
the Harney Basin of southeastern Oregon, and the plateau region of 
central and southern Oregon, as well as territory adjacent to but 
perhaps not strictly included in any of these. The Columbia Basin 
of eastern Washington and north-central Oregon has an altitude of 
1,000 to 2,000 feet. The San Joaquin and Sacramento Valleys of 
California lie much lower, the lower end of each reaching sea level 
and the upper portions being but a few hundred feet higher. 
All these areas are characterized by low precipitation. Most of 
the rain falls during the autumn, winter, and spring months instead 
of during the summer, as in the Great Plains area. The seasonal 
rainfall is small in proportion to the total precipitation. For this 
reason, among others, winter wheats are more profitable and more 
extensively grown than spring-sown wheats. Crop production is 
governed almost wholly by the quantity and distribution of the 
annual precipitation. From Table II it will be seen that the annual 
rainfall of these stations, omitting only Chico, Cal., ranges from 9.5 
to 13.5 inches. 
Summer fallowing the land or allowing the fields to lie fallow in 
alternate years is the common farm and station practice in these 
areas. Summer tillage of the fallow to prevent the growth of weeds 
and volunteer grain conserves much of the moisture which falls in 
the year of fallow to help grow the crop in the succeeding year. 
The soils of much of this area are of volcanic origin and are light 
in texture. Reference again to the data in Table II shows the soil 
at all six of the stations named to be either a sandy loam or a sandy 
clay loam. 
Owing to the altitude, the growing season is short in much of this 
territory and early varieties are desirable. This also is another 
reason why winter varieties are more satisfactory. Even in the 
California valleys, with their low altitude and extremely long grow- 
ing season, the intense heat and drought of midsummer make early 
varieties as important there as elsewhere. 
The results from six stations in the arid basin and coastal areas are 
given in this bulletin. These stations are well scattered geograph- 
